We've implemented the data domain with a good amount of success. At first, the SAN admin wanted to remove tlog and full backup scheduling from SQL Agent and use the EMC Networker software to control this. After some questions regarding the viability of the backups in the event of Networker issues, we decided that adding another layer of complexity to the backups wasnt ideal for us. We implemented the data domain by hanging a windows file share off of the appliance so that the SQL server would see if just like any other file share. Since we were already using Ola Hallengren's maintenance scripts to backup our databases, all we had to do was change the directory the script was pointing to.